refclock 28 gone wacky on me

[Mike]

On 06/09/2016 07:08 PM, Gary E. Miller wrote:
> Yo Mike!
>
> On Thu, 9 Jun 2016 18:21:32 -0400
> Mike <bellyacres at gmail.com> wrote:
>
>> Forgot this in the original post...
>>
>> ntpshmmon version 1
>> #      Name   Seen@                Clock Real               L Prec
>> sample NTP0 1465510765.147894340 1465510765.120560175  1465510764.938999891 0  -1
>> sample NTP0 1465510765.648664035 1465510765.468806532  1465510764.938999891 0  -1
>
>> Is seeing NTP0 twice like this typical?
> Nope, should be impossible.  Looks to be exactly 500 milliSec apart.
> Do you have a square wave output?  Or a 2Hz output?
>
> How about you put ppstest on it to see.  Except on the Pi you only
> see one edge, so can not tell square wave from 2 Hz.  Got a scope?
> What is the GPS again?
GPS module is a ST22, SkyTraq Venus 6 chipset.

http://www.perthold.de/BINARY/gps-st22.pdf Datasheet is here.

It's an oddball corner case I'm sure...
No scope easily available right now.
If I hook it up to a PC, or with a serial to USB adapter will I be able 
to see more about the edge being seen?

mike at rpi-ticker:~ $ sudo ppstest /dev/pps0
trying PPS source "/dev/pps0"
found PPS source "/dev/pps0"
ok, found 1 source(s), now start fetching data...
source 0 - assert 1465518012.001419932, sequence: 12052 - clear 
0.000000000, sequence: 0
source 0 - assert 1465518013.001419316, sequence: 12053 - clear 
0.000000000, sequence: 0
source 0 - assert 1465518014.001418700, sequence: 12054 - clear 
0.000000000, sequence: 0
source 0 - assert 1465518015.001418086, sequence: 12055 - clear 
0.000000000, sequence: 0
source 0 - assert 1465518016.001416472, sequence: 12056 - clear 
0.000000000, sequence: 0
source 0 - assert 1465518017.001417858, sequence: 12057 - clear 
0.000000000, sequence: 0

Mike